JP7732297B2 - Woven and knitted fabrics and their manufacturing method - Google Patents

Description

The present invention relates to woven and knitted fabrics that have a soft, fluffy texture and excellent breathability against the skin, and to a method for producing the same.

Conventionally, woven and knitted fabrics using sea-island split yarns have been used to impart a supple and soft feel compared to ordinary woven and knitted fabrics (see Patent Document 1). By removing the sea component through dyeing processing and revealing thin island component filaments, it is possible to obtain extremely supple and soft woven and knitted fabrics. However, this lacks volume for clothing, and in practice its use has been limited to non-clothing applications such as wiping cloths.

In addition, woven and knitted fabrics using blended yarns of sea-island split yarns and high-shrinkage yarns have also been proposed to achieve a fluffy feel (see Patent Document 2). This method uses high-shrinkage yarns and creates a difference in yarn length, which can impart a fluffy feel to woven and knitted fabrics. However, the use of high-shrinkage yarns inevitably results in a stiff feel in bending, and in practice this method has been limited to applications in thick suede.

On the other hand, woven and knitted fabrics using bimetal composite yarn for the island component have also been proposed (see Patent Document 3). With this method, bimetal crimps are generated in the island component after sea-removal, resulting in a soft, fluffy woven and knitted fabric. However, because ultrafine crimps are generated in the gaps at the intersection points of the woven and knitted fabrics, the surface of the woven and knitted fabric becomes flat, which inevitably results in a sticky feel when in contact with the skin, and in practice this has limited its use to down.

Thus, although sea-island split yarn can impart a soft and supple texture to woven and knitted fabrics, it lacks the volume and breathability required for widespread use in general clothing.

Japanese Unexamined Patent Publication No. 4-236931 JP 2016-180189 A JP 2020-105647 Public Relations

The object of the present invention is to provide woven and knitted fabrics that have a soft, fluffy texture and excellent breathability against the skin.

To solve these problems, the present invention has the following configuration.

That is, the present invention relates to a woven or knitted fabric containing a crimped bimetal composite yarn having a single yarn fineness of 0.5 dtex or less, and the arithmetic mean roughness Sa of the surface of the woven or knitted fabric is 5 μm or more and 100 μm or less.
In a preferred embodiment, the single yarn fineness is 0.01 dtex or more and 0.4 dtex or less.
The bimetallic composite yarn is preferably made of polyester.
The present invention also provides a method for producing a woven or knitted fabric, which comprises weaving a woven or knitted fabric using an islands-in-sea split yarn in which the island components are bimetal composite yarns, dissolving the sea component of the woven or knitted fabric to induce crimping in the bimetal composite yarns, and then water jet punching the resulting fabric.

The present invention makes it possible to obtain woven and knitted fabrics that have a soft, fluffy texture and excellent breathability that was previously unattainable.

The woven or knitted fabric of the present invention has a soft, fluffy texture due to the use of bimetal composite yarn in which the sea component of a woven or knitted fabric containing islands-in-sea split yarns in which the island components are bimetal composite yarns has been dissolved and crimped. In a configuration in which the island components are not bimetal composite yarns, crimp cannot be sufficiently expressed, and therefore a fluffy texture cannot be obtained.

In the woven or knitted fabric of the present invention before sea-removal, it is preferable to use islands-in-sea splitting yarns in a blend ratio of 30% by mass or more of the total warp and weft yarns. It is also preferable to use islands-in-sea splitting yarns in some of the warp and weft yarns, and it is even more preferable to use islands-in-sea splitting yarns in all of the warp and weft yarns.

After extensive research into how to impart skin-releasing properties to woven and knitted fabrics that have been made using islands-in-sea split yarns and have had the sea removed, it was discovered that it is important to change the surface shape of the woven and knitted fabric to achieve an arithmetic mean roughness Sa, an index of surface roughness, of 5 μm or more and 100 μm or less. By keeping the arithmetic mean roughness Sa between 5 and 100 μm, it is possible to reduce contact between the bimetal crimped yarn and the skin, resulting in woven and knitted fabrics with excellent skin-releasing properties despite their fine single yarn fineness. If Sa is less than 5 μm, the fabric will have a sticky texture. On the other hand, if Sa exceeds 100 μm, the unevenness will be too strong, resulting in a rough texture. An even more preferable range for Sa is 10 μm or more and 50 μm or less.

In the woven or knitted fabric of the present invention, the single filament fineness of the bimetal composite yarn is 0.5 dtex or less, making it possible to produce a soft woven or knitted fabric that is easy to change the surface shape of. If the single filament fineness of the bimetal composite yarn exceeds 0.5 dtex, the woven or knitted fabric with a changed surface shape will be hard and have a rough texture. A more preferable single filament fineness is 0.01 dtex or more and 0.4 dtex or less.

In addition, in the woven or knitted fabric of the present invention, it is preferable that the total fineness of the bimetal composite yarn be 20 to 250 dtex, as this achieves both a fluffy and soft feel.

In the woven or knitted fabrics of the present invention, for example, polyester-based or polyamide-based composite yarns can be used as the bimetal composite yarn, but polyester-based bimetal composite yarns are preferred because of their superior fluffy feel. Furthermore, bimetal composite yarns in which one component is polytrimethylene terephthalate or polybutylene terephthalate and the other component is polyethylene terephthalate are even more preferred because they result in finer crimps and are easier to change the surface shape of the woven or knitted fabric.

The cross section of the bimetal composite yarn can be selected from any of the following types: round, triangular, flat, hexagonal, L-shaped, C-shaped, T-shaped, W-shaped, eight-lobed, dogbone, hollow, eccentric core-sheath, etc.

In addition, the woven or knitted fabrics of the present invention may be subjected to various additional treatments, such as conventional water absorption treatments, water repellency treatments, UV protection treatments, or treatments that impart functionality such as antibacterial agents, antiviral agents, deodorizers, insect repellents, and retroreflective agents, as long as the objectives of the present invention are not impaired.

The woven or knitted fabric of the present invention can be obtained by weaving or weaving a fabric using islands-in-sea split yarns in which the island components are bimetal composite yarns, and then dissolving the sea component of the islands-in-sea composite yarns at the fabric stage (hereinafter sometimes referred to as sea removal).

The mass ratio of the two components of bimetal composite yarn is preferably 3:7 to 7:3 to fully develop crimp. A more preferred mass ratio is 4:6 to 6:4.

Furthermore, when the island component of the sea-island split yarn is polyester, it is preferable that the sea component be a polyester whose sea-removal treatment speed (alkali weight reduction speed) is at least five times faster than that of either of the two island component polyesters. A polyester that is at least eight times faster is more preferable, and a polyester that is at least ten times faster is even more preferable. By making the alkali weight reduction speed ratio at least five times faster than that of either of the two island component polyesters, incomplete sea-removal (a state in which the sea component is not completely dissolved and the island parts are fused together) in the sea-removal treatment can be easily avoided, and excellent woven or knitted fabrics with fewer defects such as dye spots and raised spots can be obtained.

Specifically, the two island component polyesters may be a combination of any known polyesters. Examples include aliphatic polyesters such as polyethylene terephthalate (hereinafter referred to as PET), polytrimethylene terephthalate, polybutylene terephthalate (hereinafter referred to as PBT), and polylactic acid. These polyesters may also contain copolymerizable components capable of forming other ester bonds, with the diol and acid components each comprising 20 mol % or less, and more preferably 10 mol % or less. Examples of copolymerizable compounds include dicarboxylic acids such as isophthalic acid, succinic acid, cyclohexanedicarboxylic acid, adipic acid, dimer acid, sebacic acid, and 5-sodium sulfoisophthalic acid, and diols such as ethylene glycol, diethylene glycol, butanediol, neopentyl glycol, cyclohexanedimethanol, polyethylene glycol, and polypropylene glycol. These polyesters may contain additives such as matting agents, flame retardants, antistatic agents, and pigments.

Since the sea component polyester forms the fiber surface of the islands-in-sea split yarn, it also needs to be strong enough to maintain stable processability. However, if the copolymerization amount of 5-sodium sulfoisophthalic acid or polyethylene glycol is too high, the raw yarn strength will decrease. Therefore, the copolymerization amount of 5-sodium sulfoisophthalic acid is preferably 1.5 mol% or more and 10 mol% or less, and the copolymerization amount of polyethylene glycol is preferably 2 mass% or more and 15 mass% or less. Furthermore, the copolymerization amount of 5-sodium sulfoisophthalic acid is more preferably 2 mol% or more and 8 mol% or less, and the copolymerization amount of polyethylene glycol is more preferably 4 mass% or more and 12 mass% or less.

The mass ratio of sea component to island component in the islands-in-sea split yarn is preferably 10/90 to 50/50 from the viewpoints of composite morphology stability, spinnability, and productivity. If the mass ratio of the sea component is too low, composite abnormalities may occur, resulting in poor splitting, or even if the dispersion morphology is normal, poor splitting may occur due to insufficient dissolution of the sea component. Conversely, if the mass ratio of the sea component exceeds 50%, productivity will decrease. A mass ratio of sea component to island component of 20/80 to 30/70 is more preferable.

When spinning the islands-in-sea split yarn described above, any process can be used, including a method in which spinning and drawing steps are carried out continuously, or a method in which the yarn is wound as an undrawn yarn and then drawn. The islands-in-sea split yarn produced in this manner can be made into a woven or knitted fabric using a known weaving or knitting method. Any known weave can be used as the weave or knitting structure, but methods that create ribs through weaving techniques may make it difficult to achieve the fluffy feel due to the crimp of the bimetal composite yarn. Preferably, woven fabrics have a relatively plain weave such as plain, twill, matte, or satin, and knit fabrics have a relatively plain weave such as jersey, smooth, half, denbigh, satin, or atlas, and the surface shape of the woven or knitted fabric is changed after sea-removal to impart surface roughness to the woven or knitted fabric.

The loom used for weaving can be any type of loom, including commonly used standard looms, rapiers, water jet looms, and air jet looms. Among these, air jet looms, which do not apply excessive tension to the weft yarn, are preferred.

Knitting machines used for knitting include, but are not limited to, circular knitting machines, tricot knitting machines, Russell knitting machines, weft knitting machines, etc.

The woven or knitted fabric is then subjected to a sea-removal process to remove the sea component from the islands-in-sea split yarn, thereby developing crimps in the bimetal composite yarn of the island component. Even if crimps are developed in the bimetal composite yarn during sea-removal, a heat treatment process to develop crimps may be performed after sea-removal. The sea-removal process preferably involves subjecting the woven or knitted fabric to alkali reduction. The reduction is preferably a process that removes all of the sea component. For example, the woven or knitted fabric is immersed in an aqueous sodium hydroxide solution (NaOH: 0.1 to 10 g/L) at 30 to 100°C. While known methods and devices can be used for alkali reduction, a sea-removal method using a jet dyeing machine is preferred, as it allows for uniform sea-removal from the fiber surface.

Even if crimping occurs in the bimetal composite yarn due to sea-removal, it is also preferable to carry out a heat treatment after the sea-removal process to impart a stronger crimp. Specifically, a relaxation treatment at 120°C or higher using a jet dyeing machine can impart a stronger crimp.

The woven or knitted fabric is then subjected to water jet punching to change the surface shape of the fabric and achieve an arithmetic mean roughness Sa of 5 to 100 μm. By adjusting the water pressure in the water jet punching, the crimp of the bimetal composite yarn is disrupted and entangled, imparting the surface roughness of the present invention, which provides good skin release properties. The preferred water pressure is 50 to 150 kg/ ^cm2 .

The fabric may then be dyed. The dyeing process can be carried out using the same dyeing processes and conditions as for general woven and knitted fabrics.

As described above, the woven or knitted fabric of the present invention has a soft, fluffy texture and excellent skin-releasing properties due to the change in the surface shape of the woven or knitted fabric after sea-removal.
The woven or knitted fabric of the present invention can be widely used for, for example, pants, coats, jackets, shirts, skirts, etc., and is particularly suitable for use as a substitute for leather.

The present invention will be explained in more detail below with reference to examples.
1. Arithmetic mean roughness Sa
Measurement was carried out in accordance with ISO 25178 under the following conditions.
Sample size: 10 cm x 10 cm (fixed to the stage without weight)
Equipment: Keyence Corporation VR-3200
Measurement area: 18mm x 24mm
Correction: Waviness removal (correction strength = 5)
Filter settings Filter type: Gaussian S-filter: None F-operation: None L-filter: None N number: Measure 10 points and use the average value as the arithmetic mean height.
2. Softness: A sensory evaluation was conducted by stroking the woven or knitted fabric with the thumb, index finger, and middle finger, and the fabric was rated on a four-point scale: very soft, very soft, slightly insufficient softness, and not soft enough and rough to the touch. The result was determined to be closest to the average of the ratings of 10 randomly selected people.
3. Fullness A sensory evaluation was conducted by stroking the woven or knitted fabric with the thumb, index finger, and middle finger, and the fullness was evaluated on a four-point scale: very good fullness, good fullness, slightly insufficient fullness, and insufficient fullness, paper-like texture. The result was determined to be closest to the average of the ratings of 10 randomly selected people.
4. Skin-releasing property In a sensory evaluation in which the woven or knitted fabric was slid over the arm, the skin-releasing property was rated on a four-point scale: very good skin-releasing property, good skin-releasing property, slightly insufficient skin-releasing property, and insufficient skin-releasing property and sticky texture. The result was determined to be closest to the average of the ratings of 10 randomly selected people.

Example 1
Two island component polymers, PBT (island 1 component) and PET (island 2 component), and a sea component polymer, polyethylene terephthalate copolymerized with 8.0 mol% of 5-sodium sulfoisophthalic acid and 10% by mass of polyethylene glycol, were melted separately and poured into a 24-island spinneret to form a side-by-side islands-in-sea composite morphology. The mass ratio of sea/island 1/island 2 components was 20/40/40. The yarn was wound at a spinning speed of 3,000 m/min to obtain an islands-in-sea composite yarn with 24 islands and 70 dtex-12 filaments.

This yarn was used for the warp and weft, and the fabric was woven using a plain weave on an air jet loom at a greige density (warp: 170 threads/2.54 cm, weft: 130 threads/2.54 cm).

Next, the obtained woven fabric was subjected to continuous open-spread scouring at 98°C, followed by a sea-removal process by immersion in a 1% by mass aqueous solution of caustic soda at 90°C, thereby inducing crimping in the polyester filaments constituting the woven fabric. The islands-in-sea composite yarn was 56 dtex-288 filaments (single yarn fineness: 0.19 dtex). The fabric was then subjected to a relaxation treatment at 130°C, an intermediate setting at 180°C, and a water jet punching process at a pressure of 100 kg/ ^cm² , followed by dyeing at 130°C and a finish setting at 160°C, yielding a woven fabric.

The resulting woven fabric had a processing density of 240 warp threads/2.54 cm and 170 weft threads/2.54 cm, and an arithmetic mean roughness Sa of 22 μm. The woven fabric also had excellent softness, fluffy feel, and excellent skin-relaxing properties.
Example 2
A woven fabric was obtained in the same manner as in Example 1, except that the water jet punching was carried out at a pressure of 60 kg/cm ² .

The resulting woven fabric had a processing density (warp: 238 threads/2.54 cm, weft: 166 threads/2.54 cm) and an arithmetic mean roughness Sa of 9 μm. The woven fabric also had excellent softness, fluffy feel, and skin-relaxing properties.
Example 3
An islands-in-sea composite yarn was obtained in the same manner as in Example 1, and a 46-gauge jersey was knitted using a single circular knitting machine.

Next, the obtained knitted fabric was subjected to continuous open-spread scouring at 98°C, followed by immersion in a 1% by mass aqueous solution of caustic soda at 90°C for sea-removal processing, thereby inducing crimping in the polyester filaments constituting the knitted fabric. The islands-in-sea composite yarn was 56 dtex-288 filaments (single yarn fineness: 0.19 dtex). Thereafter, it was subjected to a relaxation treatment at 130°C, an intermediate setting at 180°C, and a water jet punching treatment at a pressure of 130 kg/ ^cm2 , followed by dyeing at 130°C and a finish setting at 160°C, to obtain a knitted fabric.

The resulting knitted fabric had a processing density (well: 85 threads/2.54 cm, course: 49 threads/2.54 cm) and an arithmetic mean roughness Sa of 88 μm. The knitted fabric also had excellent softness, fluffy feel, and excellent skin-releasing properties.
<Comparative Example 1>
A woven fabric was obtained in the same manner as in Example 1, except for the step of performing water jet punching at a pressure of 100 kg/cm ² .

The resulting fabric had a processing density (warp: 232 threads/2.54 cm, weft: 162 threads/2.54 cm) and an arithmetic mean roughness Sa of 1 μm. Furthermore, while the fabric had excellent softness and fluffy feel, it lacked skin-releasing properties and had a sticky texture.

<Comparative Example 2>
Two types of polymers, PBT (island 1 component) and PET (island 2 component), were melted separately and poured into a 72-island spinneret to form a side-by-side composite. The mass ratio of island 1/island 2 components was 50/50. The yarn was wound at a spinning speed of 3,000 m/min to obtain 56 dtex-72 filaments (single yarn fineness: 0.78 dtex).

This yarn was used for the warp and weft, and the fabric was woven using an air jet loom in a plain weave with a greige density (warp: 170 threads/2.54 cm, weft: 130 threads/2.54 cm).

Next, the obtained woven fabric was subjected to continuous open-spread scouring at 98°C, followed by liquid flow relaxation at 130°C, intermediate setting at 180°C, and water jet punching at a pressure of 100 kg/ ^cm2 , followed by dyeing at 130°C and finishing setting at 160°C to obtain a woven fabric.

The resulting fabric had a processing density (warp: 234 threads/2.54 cm, weft: 164 threads/2.54 cm) and an arithmetic mean roughness Sa of 3 μm. Furthermore, while the fabric had excellent volume, it lacked softness and had a rough texture, and its ability to slip off the skin was somewhat lacking.

<Comparative Example 3>
PET as the island component polymer and polyethylene terephthalate copolymerized with 8.0 mol % of 5-sodium sulfoisophthalic acid and 10 mass % of polyethylene glycol as the sea component polymer were melted separately and poured into a 24-island spinneret. The mass ratio of sea/island components was 20/80. The yarn was wound at a spinning speed of 3,000 m/min to obtain a sea-island yarn with 24 islands and 70 dtex-12 filaments.

This yarn was used for the warp and weft, and the fabric was woven using an air jet loom in a plain weave with a greige density (warp: 170 threads/2.54 cm, weft: 130 threads/2.54 cm).

The resulting woven fabric was then subjected to continuous open scour at 98°C, followed by sea-removal processing by immersing it in a 1% by mass aqueous solution of caustic soda at 90°C to produce a sea-island yarn of 56 dtex-288 filaments (single yarn fineness: 0.19 dtex). This was followed by intermediate setting at 180°C and water jet punching at a pressure of 100 kg/ ^cm² , followed by dyeing at 130°C and finish setting at 160°C to obtain a woven fabric.

The resulting woven fabric had a processing density (warp: 202 threads/2.54 cm, weft: 151 threads/2.54 cm) and an arithmetic mean roughness Sa of 32 μm. Although the fabric was excellent in softness and skin-releasing properties, it lacked volume and had a paper-like feel.
<Comparative Example 4>
Two island component polymers, PBT (island 1 component) and PET (island 2 component), and a sea component polymer, polyethylene terephthalate copolymerized with 8.0 mol% of 5-sodium sulfoisophthalic acid and 10% by mass of polyethylene glycol, were melted separately and poured into a 24-island spinneret to form a side-by-side islands-in-sea composite morphology. The mass ratio of sea/island 1/island 2 components was 20/40/40. The yarn was then wound at a spinning speed of 3,000 m/min to obtain a 70 dtex-12 filament islands-in-sea composite yarn with 24 islands and a 250 dtex-48 filament islands-in-sea composite yarn with 24 islands.

Also, under the same conditions as in Comparative Example 2, 56 dtex-72 filaments (single yarn fineness: 0.77 dtex) were obtained.
The above two types of yarns were alternately used for the warp and weft, and the fabric was woven in a mat weave using an air jet loom at a greige density (warp: 170 threads/2.54 cm, weft: 130 threads/2.54 cm).

Next, the resulting woven fabric was subjected to continuous open-spread scouring at 98°C, followed by a sea-removal process by immersing it in a 1% by mass aqueous solution of caustic soda at 90°C, thereby inducing crimping in the polyester filaments that make up the woven fabric. The resulting islands-in-sea composite yarn was 56 dtex - 288 filaments (single yarn fineness: 0.19 dtex). It was then subjected to an intermediate set at 180°C, dyeing at 130°C, and a finishing set at 160°C to produce the finished product.

The resulting woven fabric had a processing density (warp: 222 threads/2.54 cm, weft: 153 threads/2.54 cm) and an arithmetic mean height Sa of 168 μm. It also had excellent skin-releasing properties, but was somewhat lacking in volume and softness, resulting in a rough texture.

Claims (6)

A woven or knitted fabric comprising a crimped bimetal composite yarn having a single yarn fineness of 0.5 dtex or less, the arithmetic mean roughness Sa of the surface of the woven or knitted fabric being 5 μm or more and 100 μm or less, and the woven or knitted fabric having a weave selected from the group consisting of plain, twill, matte, satin, jersey, smooth, half, denbigh, satin, and atlas . The woven or knitted fabric according to claim 1, wherein the single yarn fineness is 0.01 dtex or more and 0.4 dtex or less. The woven or knitted fabric according to claim 1 or 2, wherein the bimetal composite yarn is made of polyester. 3. The woven or knitted fabric according to claim 1, wherein the woven or knitted fabric is obtained by water jet punching. 3. The method for producing a woven or knitted fabric according to claim 1, wherein a woven or knitted fabric is produced using an islands-in-sea split yarn in which the island component yarn is a bimetal composite yarn, and then the sea component of the woven or knitted fabric is dissolved to induce crimping in the bimetal composite yarn, followed by water jet punching. 6. The method for producing a woven or knitted fabric according to claim 5 , wherein the bimetal composite yarn is made of polyester.